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authorLinus Torvalds <torvalds@linux-foundation.org>2023-01-01 11:19:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-01-01 11:19:50 -0800
commit5b129817aedb03d94fb960e7a34d0f5eaa20a2f2 (patch)
tree618e7fe0a1c25fb381e86506735076fca0e2d09b
parent95d248d16f9cb42de717367832cffa0f83e97fde (diff)
parent63dc6325ff41ee9e570bde705ac34a39c5dbeb44 (diff)
Merge tag 'x86_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov: - Two fixes to correct how kprobes handles INT3 now that they're added by other functionality like the rethunks and not only kgdb - Remove __init section markings of two functions which are referenced by a function in the .text section * tag 'x86_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kprobes: Fix optprobe optimization check with CONFIG_RETHUNK x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK x86/calldepth: Fix incorrect init section references
-rw-r--r--arch/x86/kernel/callthunks.c4
-rw-r--r--arch/x86/kernel/kprobes/core.c10
-rw-r--r--arch/x86/kernel/kprobes/opt.c28
3 files changed, 17 insertions, 25 deletions
diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c
index 7d2c75ec9a8c..ffea98f9064b 100644
--- a/arch/x86/kernel/callthunks.c
+++ b/arch/x86/kernel/callthunks.c
@@ -119,7 +119,7 @@ static bool is_coretext(const struct core_text *ct, void *addr)
return within_module_coretext(addr);
}
-static __init_or_module bool skip_addr(void *dest)
+static bool skip_addr(void *dest)
{
if (dest == error_entry)
return true;
@@ -181,7 +181,7 @@ static const u8 nops[] = {
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
};
-static __init_or_module void *patch_dest(void *dest, bool direct)
+static void *patch_dest(void *dest, bool direct)
{
unsigned int tsize = SKL_TMPL_SIZE;
u8 *pad = dest - tsize;
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 66299682b6b7..b36f3c367cb2 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -37,6 +37,7 @@
#include <linux/extable.h>
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
+#include <linux/kgdb.h>
#include <linux/ftrace.h>
#include <linux/kasan.h>
#include <linux/moduleloader.h>
@@ -281,12 +282,15 @@ static int can_probe(unsigned long paddr)
if (ret < 0)
return 0;
+#ifdef CONFIG_KGDB
/*
- * Another debugging subsystem might insert this breakpoint.
- * In that case, we can't recover it.
+ * If there is a dynamically installed kgdb sw breakpoint,
+ * this function should not be probed.
*/
- if (insn.opcode.bytes[0] == INT3_INSN_OPCODE)
+ if (insn.opcode.bytes[0] == INT3_INSN_OPCODE &&
+ kgdb_has_hit_break(addr))
return 0;
+#endif
addr += insn.length;
}
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index e6b8c5362b94..e57e07b0edb6 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -15,6 +15,7 @@
#include <linux/extable.h>
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
+#include <linux/kgdb.h>
#include <linux/ftrace.h>
#include <linux/objtool.h>
#include <linux/pgtable.h>
@@ -279,19 +280,6 @@ static int insn_is_indirect_jump(struct insn *insn)
return ret;
}
-static bool is_padding_int3(unsigned long addr, unsigned long eaddr)
-{
- unsigned char ops;
-
- for (; addr < eaddr; addr++) {
- if (get_kernel_nofault(ops, (void *)addr) < 0 ||
- ops != INT3_INSN_OPCODE)
- return false;
- }
-
- return true;
-}
-
/* Decode whole function to ensure any instructions don't jump into target */
static int can_optimize(unsigned long paddr)
{
@@ -334,15 +322,15 @@ static int can_optimize(unsigned long paddr)
ret = insn_decode_kernel(&insn, (void *)recovered_insn);
if (ret < 0)
return 0;
-
+#ifdef CONFIG_KGDB
/*
- * In the case of detecting unknown breakpoint, this could be
- * a padding INT3 between functions. Let's check that all the
- * rest of the bytes are also INT3.
+ * If there is a dynamically installed kgdb sw breakpoint,
+ * this function should not be probed.
*/
- if (insn.opcode.bytes[0] == INT3_INSN_OPCODE)
- return is_padding_int3(addr, paddr - offset + size) ? 1 : 0;
-
+ if (insn.opcode.bytes[0] == INT3_INSN_OPCODE &&
+ kgdb_has_hit_break(addr))
+ return 0;
+#endif
/* Recover address */
insn.kaddr = (void *)addr;
insn.next_byte = (void *)(addr + insn.length);